The long range goal of our proposed research is to understand the details of the HIV assembly process at a molecular level to provide the groundwork for rationale drug design. Towards achieving this goal, the research proposed in this program focuses on several key but no-so-well understood aspects of the HIV assembly process. The formation of HIV particles is complex and involves the interaction of several different virus-specified components. Because of this it seems likely that as we learn more about assembly, many novel targets for anti HIV drugs will emerge. Although the overall outline of HIV assembly is understood, many of the details are lacking. Specifically we are interested in; 1) defining in detail how the HIV core protein precursors interact to form virus particles. 2) Studying the effect of the viral envelope proteins and vpu on virus release and assembly and examining the mechanisms which underlie the targeting of the viral envelope proteins and core precursors to apposing sites of the plasma membrane 3) Determining in more detail than is presently known how viral RNA is packaged and. 4) Comparing the assembly process for HIV-1 to HIV-2. to determine if "phenotypic mixing" between these two viruses can occur.